Nail psoriasis: what is it, symptoms, treatment

Psoriasis—the inflammatory skin disease that creates red, itchy plaques on the skin—can take many forms. There are different types of psoriasis that can bring changes to the tissues throughout the body. You may notice red areas on the scalp, the achy joints of psoriatic arthritis, or changes in your fingernails and toenails—a potential sign of nail psoriasis.

Nail psoriasis is often characterized by nails that are pitting, lifting, or have thick, discolored nail buildup (Haneke, 2017). If your healthcare provider has diagnosed you with nail psoriasis, it’s important to know that you’re not alone. 

Of the more than 7.5 million American adults who have skin psoriasis, medical experts estimate that up to 90% will have psoriasis of the nails at some point in their lives (Haneke, 2017). At the same time, some people who have nail changes and who’ve never had skin lesions can end up with the wrong diagnosis. 

Here’s how to spot the signs of nail psoriasis, a look at its causes, and new treatment options.

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Psoriasis can occur anywhere on your body, including your finger and toe nails. Nail psoriasis is a chronic inflammatory condition that speeds the growth of nails leading to thick buildup, discoloration, cracking, and lifting from the nail bed. This can affect one or two nails or many nails on both the fingers and toes. It can also range from mild and hardly noticeable to severe, leading to nail loss (Haneke, 2017). 

It often occurs at the same time or years after the start of skin psoriasis, known as cutaneous psoriasis. An example of skin psoriasis is plaque psoriasis, which causes red, scaly plaques. Nail psoriasis is also directly linked to psoriatic arthritis, a destructive joint condition (Haneke, 2017). 

When nail psoriasis is flaring up and damaging the fingernails or toenails, it can affect the tissue that creates the nails. It can also change the nail bed below the nail, which keeps the nail attached. You may notice the following signs with nail psoriasis (Haneke, 2017; Sobolewski, 2017):

Nail changes: 

• Pitting (pinpricks) 

• White lines or dots (leukonychia)

• Red spots at the base of the nail 

• Nail plate crumbling

• Deformed nails

• Vertical lines with splitting 

• Horizontal indented lines (Beau lines)

Nail bed changes: 

• Separation of the nail from the nail bed (onycholysis)

• Oil-drop discoloration (also called salmon spots)

• Nail bed thickening; chalky buildup (subungual hyperkeratosis)

• Thin red or reddish-brown lines that look like splinters (blood) 

In its most severe form, the condition can be painful, making it hard to use the hands. Additionally, nails will typically break easily. Many people will also get a fungal infection called onychomycosis, making the condition worse (Sobolewski, 2017).  

Like psoriasis of the skin, nail psoriasis involves overactive T-cells—a type of white blood cell. They help trigger an immune response that attacks normal tissues of the skin or nails, resulting in inflammation that causes them to produce cells more rapidly than usual.  On the skin, the result is red plaques; on the nails, the result is pitting, buildup, and discoloration (von Stebut, 2020; Furue, 2020).

Nail psoriasis, like psoriasis, is known to run in families, especially in cases that begin in childhood (Haneke, 2017). At least 60 genetic markers have a link to an increased risk of psoriasis. However, there’s not a strong enough genetic factor that typically causes psoriasis or nail psoriasis outright. Instead, genetics combined with health risk factors, and triggers like infections and injuries, appear to lead to flare-ups (Rendon, 2019; Chen, 2017).

Psoriasis has known triggers, ranging from infections and smoking to medications and stress. It’s not entirely clear how these boost risk for nail psoriasis. According to the American Academy of Dermatology Association, once you have psoriasis, additional triggers like a sunburn increase the chances of getting another type of psoriasis (AAD, 2021). 

Research shows that strep throat and staph infections can trigger psoriasis (Teng, 2021). It also shows that the fungus Candida albicans, common in human bodies and on the skin and nails, may have a similar effect. When it overpopulates and turns into an infection (candidiasis), it can trigger and worsen skin psoriasis (Ventura, 2017; CDC, 2020 ). 

There is a link between skin and nail injuries and both psoriasis and nail psoriasis. In one case, a woman had surgery on her hand at the base of the fingers and ended up with nail psoriasis on three nails closest to the incisions (Afshar, 2017). 

Other risks that can boost the chances of an initial skin psoriasis flare: heavy alcohol use and obesity (Kamiya, 2019; Szentkereszty-Kovács, 2021).

A diagnosis of psoriatic nail disease is pretty straightforward for those who have already been diagnosed with another type of psoriasis. However, about 5-10% of those with nail psoriasis don’t have skin or joint involvement, which increases the chance of misdiagnosis (Choudhary, 2021; Haneke, 2017).

A diagnosis includes an exam of the skin, nails, and scalp, along with a discussion about family history, lifestyle, and any potential joint or nail pain. Your healthcare provider may also take a nail biopsy if the diagnosis is in question because it’s important to rule out and treat other types of nail conditions first. Often, fungal infections are diagnosed with nail psoriasis. In these cases, a healthcare provider treats the fungal infection first because some psoriasis treatments can increase the risk of fungal and other infections (Muneer, 2021).

There are various tools designed to track nail psoriasis treatments. The Nail Area Psoriasis Severity Index (NAPSI) divides the nail into sections with scores ranging from 0-8 per nail with 160 for all 20 nails. It’s combined with the dermatology life quality index (DLQI) to help track how the treatment alters the nails and daily life. These tools can help track progress and guide treatment (Prevezas, 2019). 

Healthcare providers base the treatment of nail psoriasis on nail involvement, the severity of the disease, current quality of life, and goals for treatments. A referral to a healthcare provider specializing in dermatology can improve the overall management of the disease (Muneer, 2021).

Mild-to-moderate cases

For mild to moderate nail psoriasis, there are a variety of topical treatments (corticosteroids, Vitamin D,  tazarotene, tacrolimus) (Muneer, 2021; Pasch, 2016)

Corticosteroid or methotrexate injections into the nails have shown to be more effective than topicals alone. Studies have also shown that psoralen UVA (PUVA) phototherapy and pulse dye lasers can help reduce nail psoriasis (Choudhary, 2021; Duarte, 2019).

Severe cases

If nail damage is severe and there are also problems with psoriatic skin or joints, your healthcare provider will likely suggest systemic drugs, meaning they work throughout the body. This could involve the newer so-called “biologics” that target a specific part of your immune system (etanercept, adalimumab, infliximab, ustekinumab, secukinumab, Ixekizumab) or other immune-modulating drugs like methotrexate, apremilast, cyclosporine, or acitretin (Pasch, 2016; Chan, 2017; Brownstone, 2021). 

New biologic drugs are effective at treating moderate to severe psoriasis—leading to a clearing of skin lesions and a dramatic improvement in affected nails. However, they increase the risk of infections like tuberculosis and fungal skin infections (Kamata, 2020). 

Seeing results from any type of treatment usually takes 3-9 months due to the slow growth of nails (Pasch, 2016).

While there is no cure for nail psoriasis, there are ways to prevent flare-ups by reducing the chances of injuries and infections. Dermatologists suggest the following nail care approaches  (Muneer, 2021; AAD, 2021):

• Apply moisturizers to the skin around nails

• Regularly trim nails (to prevent injury, lifting)

• Wear gloves or wide toed shoes when doing manual work (to prevent trauma/infections)

• Do not trim cuticles, bite, or pick nails (cuts can trigger a flare-up)

• Don’t scrape under nails (can cause nail lifting)

• Avoid artificial nails (can lead to nail lifting)

• Nail polish and light buffing are fine

Since nail psoriasis is similar to skin psoriasis, avoiding psoriasis triggers and preventing risk factors with lifestyle changes can also help. Nail psoriasis can be stubborn. Fortunately, there are increasing options to bring back healthier nails. 

If you have questions about living with nail psoriasis, the National Psoriasis Foundation works to provide answers ranging from what to expect from treatments to how to find support groups. If you suspect you may have nail psoriasis, talk to a healthcare provider who can help you address your concerns.

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Current version

October 04, 2021

Written by

Kristin DeJohn

Fact checked by

Felix Gussone, MD

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About the medical reviewer

Felix Gussone, MD, Ro

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.